Nano Punch Cards

IBM has retooled punch cards for the coming nanotechnology age. Code-named Millipede, IBM 's new prototype of a nanomechanical storage device uses thousands of tips (see photo) to punch indentations into a plastic strip, with each indentation representing 1 bit. IBM researchers claim that the plastic strip can fit the storage equivalent of 25 DVD discs onto an area no bigger than a postage stamp.

Millipede can write, read, erase, and rewrite data to the thin plastic strips. To write data, a tip is heated to 400 degrees Celsius and sunk into a thin layer of plexiglass atop a silicon chip, creating an indentation; to read data, the same tip is heated to 300 degrees Celsius, which does not affect the strip as the tip passes along and notes the indents. Erasing data involves creating offset indents that fill the old ones.

With the Millipede prototype, IBM researchers have achieved a storage density of 1 trillion bits per square inch, which is 20 times that of today's densest magnetic storage capabilities. Millipede won't be manufactured in volume for another two years. The technology promises to store data in spaces smaller than electrical and magnetic storage formats can reliably function in, given their physical limits.